1. Field of the Invention
This invention relates to image analysis apparatus and methods for extracting and processing a multiplicity of data from an image by using, in general a parallel line raster scan and more specifically it relates to image analysis systems and methods for extracting data from an image over an initial and subsequent fields of view and to correlate the extracted data to thereby enable a wide range of measurements to be performed on the feature of the image.
2. Description of the Prior Art
Techniques for extracting data from fields of scan of images or objects to be measured have generally been based on deriving the data without reference to data extracted in prior fields of view. This has tended to limit the capability and flexibility of image analysis systems becuse it was not always possible to extract from a single field of view all the information desired from the features being measured. Alternatively, it has required that information representing video signals from the entire field of scan be stored before processing of the video signals commences.
In the techniques described herein and in the concurrently filed application entitled, Image Analysis Data Transfer and also the concurrently filed application entitled, Image Analysis Data Extraction, data is extracted from an initial field of scan and it is used to control, during subsequent fields of scan, the extraction of data in those fields. This permits the accumulation of data from a particular image using repetitive scanning in such a manner that data extracted from subsequent fields of scan may be correlated between various fields of scan. This in turn provides for the extraction of more complex information and measurements from the features. The correlation is performed by means of indexing techniques, such indexing being set up on an initial field of view.
Prior techniques have not permitted the indexed extraction of data on subsequent fields of view, thereby restricting the range of both measurements and analysis which can be performed on a specific image. Prior patents, for example, U.S. Pat. No. 3,805,028, entitled Methods of and Apparatus for Determining the Quantity and Physical Parameters of Objects, issued Apr. 16, 1974 for inventor R. Morton, and U.S. Pat. No. 3,624,604 entitled Image Analysis, issued Nov. 30, 1971 to inventor D. W. Gibbard, disclose techniques for extracting data and correlating it from successive fields of view. However, neither discloses techniques for extracting and storing coordinate data in an initial field of view for later indexing with the information extracted from successive fields of view when scanning the image.